Shizuka is a policewoman who loves her silencer more than anything. Back in Japan after an internship in the United States, she is ban from the police. Transferred to the sordid "Security Annex Office", she has to team with a corrupt and pervers coworker. During a trivial investigation, she witnesses an atrocious murder and decides to lead the investigation. She does not know it yet, but she's going ahead a terrible threat!